Last major update issued on February 7, 2010 at 13:30 UTC.
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The geomagnetic field was quiet to unsettled on February 6. Solar wind speed ranged between 304 and 405 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 87.5. The planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.0). Three hour interval K indices: 00002311 (planetary), 00012321 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 2 spotted regions on the visible solar disk.
Region 11043 was quiet and stable.
New region 11045 emerged on February 5 and was numbered by NOAA/SWPC the next day. The region continues to develop rapidly and has a complex magnetic layout with a significant delta configuration in the central spot section. Expect further M class flaring with a chance of a small X class event. Further Earth directed CMEs are likely. Flares: C4.0 at 07:04, C1.0 at 10:48, C3.4 at 15:39, M2.9 at 18:59, M1.3 at 21:37, C2.2 at 22:31, C2.7 at 22:59 UTC. On February 7 a major M6.4/1N flare was recorded at 02:34 UTC. This event was associated with a large CME which is very likely to impact Earth, probably on February 9.
February 4-5: No obvious partially or fully Earth directed CMEs were observed in LASCO
or STEREO imagery.
February 6: A CME was observed after the M2 flare in region 11045.
Coronal hole history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A recurrent coronal hole (CH390) in the northern hemisphere was in an Earth facing position on February 6-7. A coronal hole in the southern hemisphere could reach an Earth facing position on February 8.
Processed SOHO/EIT 195 image at 02:24 UTC on February 7. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is good. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be mostly quiet on February 7-8. The CME associated with the major flare in region 11045 could impact Earth on February 9 and cause major geomagnetic storming. A high speed stream from CH390 could cause unsettled to active conditions on February 10.
|Coronal holes (1)||Coronal mass ejections (2)||M and X class flares (3)|
1) Effects from a coronal hole could reach Earth
within the next 5 days. When the high speed stream has arrived the
color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.
Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability.
Compare to the previous day's image.
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.
|Active region||Date numbered||SWPC
|Location at midnight||Area||Classification||Comment|
|11045||2010.02.06||9||15||N24E15||0290||DKC||formerly region S750
|Total spot count:||10||16|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average Ap
cycle 23 sunspot max.
|2009.08||67.3||0.0||(4.5 predicted, +0.9)||5.70|
|2009.09||70.5||4.2||(5.5 predicted, +1.0)||3.88|
|2009.10||72.6||4.6||(6.6 predicted, +1.1)||3.66|
|2009.11||73.6||4.2||(7.8 predicted, +1.2)||2.45|
|2009.12||76.7||10.6||(9.2 predicted, +1.4)||1.41 / 1.92|
|2010.01||81.1||13.1||(11.0 predicted, +1.8)||2.93|
|2010.02||77.3 (1)||3.6 (2)||(13.0 predicted, +2.0)||(5.58)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SWPC) sunspot number. The official international sunspot number is typically 30-50% lower.
3) Running average based on the daily SWPC ap indices. Values in red are based on official NGDC records.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.